function processClass(searchClass) {
  var myWidth = 0, myHeight = 0;
  if( typeof( window.innerWidth ) == 'number' ) {
    //Non-IE
    myWidth = window.innerWidth;
    myHeight = window.innerHeight;
  } else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
    //IE 6+ in 'standards compliant mode'
    myWidth = document.documentElement.clientWidth;
    myHeight = document.documentElement.clientHeight;
  } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
    //IE 4 compatible
    myWidth = document.body.clientWidth;
    myHeight = document.body.clientHeight;
  }

	if (myWidth < 660 || myHeight < 520) {
		var replaceStr = '/files/480x300_';
	}
	else if (myWidth < 820 || myHeight < 660) {
		var replaceStr = '/files/640x480_';
	}
	else if (myWidth < 1040 || myHeight < 840) {
		var replaceStr = '/files/800x600_';
	}
	else if (myWidth < 1600 || myHeight < 1200) {
		var replaceStr = '/files/1024x768_';
	}
	else {
		return;
	}

	var classElements = new Array();
	node = document;
	tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp('(^|\\\\s)'+searchClass+'(\\\\s|$)');
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
			els[i].href = els[i].href.replace(/\/files\/([0-9]+x[0-9]+_)?/, replaceStr);
		}
	}
}